android - Kotlin 'it' syntax in the context of Volley -


can explain me how kotlin 'it' syntax in snippet of code works? code hard read, sent me fix problem , works magic multiple consecutive requests. have used volley before code confusing. believe kotlin easier read java particular code hard understand.

val responses = mutablelistof<jsonobject>() val myapiurl = "https://maps.googleapis.com/maps/api/distancematrix/json?units=metric&origins=" val myapikey = "removed" val transportmode = listof("&mode=driving", "&mode=walking", "&mode=bicycling",             "&mode=transit&transit_mode=bus", "mode=transit&transit_mode=subway", "mode=transit&transit_mode=train")  val queue = volley.newrequestqueue(this)  transportmode.map { "$myapiurl$locationcoordinateslat,$locationcoordinateslong&destinations=$locationinput$it&key=$myapikey" }             .map {                 jsonobjectrequest(request.method.get, it, null, response.listener {                     responses.add(it)                 }, response.errorlistener {                    //nothing                 })             }.foreach { queue.add(it) } }

first, each entry in transportmode list mapped same string "$myapiurl$locationcoordinateslat,$locationcoordinateslong&destinations=$locationinput$it&key=$myapikey", throwing away transport mode. let's call a.

then, resulting list of these strings mapped jsonobjectrequests, url set it, 1 of strings a of list. each jsonobjectrequest has success callback , error callback. former receives resulting jsonobject implicit it parameter, responses.add(it) adds jsonobject list of responses.

the last it can found in lambda function passed foreach. it's 1 of jsonobjectrequest objects created in last map-step. lambda adds volley request queue.

to make things clearer, i've augmented code hints:

transportmode.map { mode -> "$myapiurl$locationcoordinateslat,$locationcoordinateslong&destinations=$locationinput$it&key=$myapikey" }         .map { url ->             jsonobjectrequest(request.method.get, url, null, response.listener { responsejsonobject ->                 responses.add(responsejsonobject)             }, response.errorlistener {                //nothing             })         }.foreach { request -> queue.add(request) }

Comments

Post a Comment

Popular posts from this blog

Is there a better way to structure post methods in Class Based Views -

i'm using class based views in django , never specify url in ajax calls , omit action parameter in form because know these requests go through post method of class based view. notice view - profile page make many requests depending on user updating on page - post method become convoluted , if/else mess example: def post(self, request, *args, **kwargs): # handle user changing available date if request.post.get('availabledate') != none: self.updateavailabledate(request) return jsonresponse({'result':'success'}) if request.post.get('newprojectname') != none: creative_user = creativeuserprofile.objects.get(id = request.user.id) project = project.create_project(creative_user, request.post['newprojectname']) project.save() return jsonresponse({'projectid': project.id }) if request.post.get('projectimage') != none , request.files['file']: proj
Read more

performance - Why is XCHG reg, reg a 3 micro-op instruction on modern Intel architectures? -

i'm doing micro-optimization on performance critical part of code , came across sequence of instructions (in at&t syntax): add %rax, %rbx mov %rdx, %rax mov %rbx, %rdx i thought had use case xchg allow me shave instruction , write: add %rbx, %rax xchg %rax, %rdx however, dimay found agner fog's instruction tables , xchg 3 micro-op instruction 2 cycle latency on sandy bridge, ivy bridge, broadwell, haswell , skylake. 3 whole micro-ops , 2 cycles of latency! 3 micro-ops throws off 4-1-1-1 cadence , 2 cycle latency makes worse original in best case since last 2 instructions in original might execute in parallel. now... cpu might breaking instruction micro-ops equivalent to: mov %rax, %tmp mov %rdx, %rax mov %tmp, %rdx where tmp anonymous internal register , suppose last 2 micro-ops run in parallel latency 2 cycles. given register renaming occurs on these micro-architectures, though, doesn't make sense me done way. why wouldn't register renamer
Read more

jquery - Responsive Navbar with Sub Navbar -

good day, forgive me nav vocabulary not best. if question confusing apologize. i'm working on navigation bar needs centered on page @ 768px , above. items in nav open (or perhaps toggle) subnav lives directly below. these nav should appear centered on page. i have been able work through responsive portion of nav bar, having main items align vertically , sub nav menu of each item roll out below, , gave them indent separation. working well. however, issue not responsive side, behavior @ width greater 768px. happens toggling menu's sub navigation pushes other main items down page below sub nav. here's code: $(document).ready(function () { //stick in fixed 100% height behind navbar don't wrap $('#slide-nav.navbar-inverse').after($('<div class="inverse" id="navbar-height-col"></div>')); $('#slide-nav.navbar-default').after($('<div id="navbar-height-col"></d
Read more